JP5618706B2 - Stacked battery - Google Patents

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JP5618706B2
JP5618706B2 JP2010190085A JP2010190085A JP5618706B2 JP 5618706 B2 JP5618706 B2 JP 5618706B2 JP 2010190085 A JP2010190085 A JP 2010190085A JP 2010190085 A JP2010190085 A JP 2010190085A JP 5618706 B2 JP5618706 B2 JP 5618706B2
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electrode
positive electrode
main body
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electrodes
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JP2012048989A (en
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末次 金井
末次 金井
和弘 藤川
和弘 藤川
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Hitachi Maxell Energy Ltd
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Priority to JP2010190085A priority Critical patent/JP5618706B2/en
Priority to KR1020137004816A priority patent/KR101318824B1/en
Priority to US13/819,172 priority patent/US9017856B2/en
Priority to CN201180041409.2A priority patent/CN103069615B/en
Priority to PCT/JP2011/068922 priority patent/WO2012026443A1/en
Priority to EP11819906.6A priority patent/EP2610945B1/en
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0413—Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0422—Cells or battery with cylindrical casing
    • H01M10/0427—Button cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0436—Small-sized flat cells or batteries for portable equipment
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0463—Cells or batteries with horizontal or inclined electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/54—Connection of several leads or tabs of plate-like electrode stacks, e.g. electrode pole straps or bridges
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/574—Devices or arrangements for the interruption of current
    • H01M50/579—Devices or arrangements for the interruption of current in response to shock
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M6/00—Primary cells; Manufacture thereof
    • H01M6/42—Grouping of primary cells into batteries
    • H01M6/46—Grouping of primary cells into batteries of flat cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/463—Separators, membranes or diaphragms characterised by their shape
    • H01M50/466—U-shaped, bag-shaped or folded
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H01M50/491—Porosity
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Description

本発明は、第１の電極と第２の電極とが積層された積層型電池に関する。   The present invention relates to a stacked battery in which a first electrode and a second electrode are stacked.

従来より、第１の電極と第２の電極とが積層された積層型電池が知られている。このような積層型電池では、例えば特許文献１に開示されるように、正極極板と負極極板とが交互に積層されているとともに、該正極極板及び負極極板からそれぞれ突出する集電タブによって電池外部と接続されている。また、前記特許文献１に開示されるように、上述のような積層型電池では、正極極板と負極極板との間にセパレータと呼ばれる絶縁材が配置されていて、該正極極板と負極極板との間の短絡の発生を防止するように構成されている。   Conventionally, a stacked battery in which a first electrode and a second electrode are stacked is known. In such a stacked battery, for example, as disclosed in Patent Document 1, positive electrode plates and negative electrode plates are alternately stacked, and current collectors projecting from the positive electrode plate and the negative electrode plate, respectively. It is connected to the outside of the battery by a tab. Further, as disclosed in Patent Document 1, in the stacked battery as described above, an insulating material called a separator is disposed between the positive electrode plate and the negative electrode plate, and the positive electrode plate and the negative electrode It is comprised so that generation | occurrence | production of the short circuit between electrode plates may be prevented.

特開２００９−１８１８９８号公報JP 2009-181898 A

ところで、上述のように、複数の電極が積層された積層型電池の場合には、落下等の衝撃が加わると、電極の重さの影響を受けて集電タブ（接続部）に大きな力が加わるため、接続部で破断する可能性が高い。該接続部が破断すると、その破断部分がもう一方の電極に接触して短絡を生じる可能性がある。   By the way, in the case of a stacked battery in which a plurality of electrodes are stacked as described above, when an impact such as dropping is applied, a large force is exerted on the current collecting tab (connecting portion) due to the influence of the weight of the electrodes. Therefore, there is a high possibility of breakage at the connecting portion. When the connecting portion breaks, the broken portion may come into contact with the other electrode to cause a short circuit.

そのため、積層型電池において、衝撃が加わって電極の接続部が破断した場合でも、該接続部の破断部分で短絡が発生するのを防止できる構成を得ることにある。   For this reason, in the stacked battery, even when an impact is applied and the connection portion of the electrode is broken, it is possible to obtain a configuration that can prevent a short circuit from occurring at the broken portion of the connection portion.

本発明の一実施形態にかかる積層型電池は、平板状の第１の電極と、該第１の電極とは極性が異なる平板状の第２の電極とを備え、前記第１及び第２の電極は、それぞれ、本体部と、平面視で該本体部から外方へ延びる接続部とを有し、該接続部が異なる方向に延びるように前記第１及び第２の電極の本体部同士が厚み方向に積層されていて、前記第１の電極の接続部は、固定部材に固定されており、前記第１の電極の接続部には、前記第１及び第２の電極板を重ね合わせた状態で、平面視で該第２の電極の本体部外方の位置に、該第１及び第２の電極に衝撃が加わった際に破断する破断部が設けられている（第１の構成）。   A stacked battery according to an embodiment of the present invention includes a flat plate-like first electrode and a flat plate-like second electrode having a polarity different from that of the first electrode, and the first and second electrodes are provided. Each of the electrodes has a main body portion and a connection portion extending outward from the main body portion in plan view, and the main body portions of the first and second electrodes are arranged so that the connection portions extend in different directions. Laminated in the thickness direction, the connection portion of the first electrode is fixed to a fixing member, and the connection portion of the first electrode is overlapped with the first and second electrode plates. In a state, a fracture portion that is broken when an impact is applied to the first and second electrodes is provided at a position outside the main body portion of the second electrode in plan view (first configuration). .

以上の構成により、第１及び第２の電極に対して衝撃が加わって、該第１の電極の接続部が破断部で破断した場合でも、破断した部分が第２の電極に接触して短絡を生じるのを防止できる。すなわち、前記第１の電極は、その接続部の破断部が平面視で前記第２の電極よりも外方に位置するように設けられているため、接続部が該破断部で破断されても、その破断部分が第２の電極に接触するのを防止できる。   With the above configuration, even when an impact is applied to the first and second electrodes and the connecting portion of the first electrode is broken at the broken portion, the broken portion contacts the second electrode and is short-circuited. Can be prevented. In other words, the first electrode is provided so that the fracture portion of the connection portion is positioned outward from the second electrode in a plan view, so that even if the connection portion is broken at the fracture portion, The broken portion can be prevented from coming into contact with the second electrode.

前記第１の構成において、前記破断部は、前記第１の電極の接続部における本体部との接続部分のうち、最も幅の狭い部分であるのが好ましい（第２の構成）。これにより、第１の電極の接続部における本体部との接続部分において、破断部の断面が最も小さくなるため、衝撃が加わった場合に、該接続部分を破断部で破断させることができる。   In the first configuration, the fracture portion is preferably the narrowest portion of the connection portion with the main body portion in the connection portion of the first electrode (second configuration). Thereby, since the cross section of a fracture | rupture part becomes the smallest in the connection part with the main-body part in the connection part of a 1st electrode, when an impact is added, this connection part can be fractured | ruptured by a fracture | rupture part.

前記第２の構成において、前記接続部分には、前記本体部から前記破断部に向かって徐々に幅が狭くなるようにＲ部が形成されているのが好ましい（第３の構成）。これにより、接続部の本体部との接続部分において、応力集中によって破断部以外の部分に大きな応力が発生して破断するのを防止できる。   In the second configuration, it is preferable that an R portion is formed in the connection portion so that the width gradually decreases from the main body portion toward the fracture portion (third configuration). Thereby, in a connection part with a main-body part of a connection part, it can prevent that a big stress generate | occur | produces in parts other than a fracture | rupture part by a stress concentration, and fractures.

前記第１の構成において、前記破断部は、前記第１の電極の接続部に設けられた切り欠き部であるのが好ましい（第４の構成）。こうすることで、破断部でより確実に接続部を破断することができるため、破断した部分と第２の電極との間で短絡が発生するのをより確実に防止できる。   In the first configuration, the fracture portion is preferably a notch provided in a connection portion of the first electrode (fourth configuration). By carrying out like this, since a connection part can be more reliably fractured | ruptured by a fracture | rupture part, it can prevent more reliably that a short circuit generate | occur | produces between the fracture | ruptured part and a 2nd electrode.

前記第１から第４の構成のうちいずれか一つの構成において、前記第２の電極の本体部は、その外形が平面視で前記第１の電極の本体部の外形よりも大きくてもよい（第５の構成）。このような構成の場合にも、第１の電極の接続部における破断部を、平面視で第２の電極の本体部の外方に位置付けることにより、第１の電極の破断部分が第２の電極に接触するのを防止できる。すなわち、上述のように、第１の電極の接続部が破断した場合に破断部分が第２の電極と接触して短絡を生じやすいような構成においても、上述の第１から第４の構成を適用することにより、電極同士の間で短絡が発生するのを防止できる。   In any one of the first to fourth configurations, the main body portion of the second electrode may have an outer shape larger than the outer shape of the main body portion of the first electrode in plan view ( Fifth configuration). Even in such a configuration, the fracture portion of the connection portion of the first electrode is positioned outside the main body portion of the second electrode in plan view, so that the fracture portion of the first electrode is the second portion. Contact with the electrode can be prevented. That is, as described above, even in a configuration in which when the connection portion of the first electrode is broken, the broken portion is likely to come into contact with the second electrode to cause a short circuit, the above-described first to fourth configurations are used. By applying, it is possible to prevent a short circuit from occurring between the electrodes.

前記第１から第５の構成のうちいずれか一つの構成において、前記第１及び第２の電極を積層してなる積層体を収納するためのケース部材を備え、前記固定部材は、前記ケース部材であるのが好ましい（第６の構成）。また、前記第１から第５の構成のうちいずれか一つの構成において、前記第１及び第２の電極を積層してなる積層体を覆うためのシート部材を備え、前記第１及び第２の電極の接続部のうち少なくとも一方は、外部端子を介して前記固定部材に固定されているのが好ましい（第７の構成）。   In any one of the first to fifth configurations, the case member includes a case member for housing a laminate formed by laminating the first and second electrodes, and the fixing member is the case member. Is preferable (sixth configuration). Further, in any one of the first to fifth configurations, a sheet member for covering a stacked body formed by stacking the first and second electrodes is provided, and the first and second It is preferable that at least one of the electrode connecting portions is fixed to the fixing member via an external terminal (seventh configuration).

前記第１から第７の構成のうちいずれか一つの構成において、前記第１の電極は、リチウムイオンを吸蔵及び放出可能な正極材を有し、前記第２の電極は、リチウムイオンを吸蔵及び放出可能な負極材を有するのが好ましい（第８の構成）。   In any one of the first to seventh configurations, the first electrode includes a positive electrode material capable of inserting and extracting lithium ions, and the second electrode stores and absorbs lithium ions. It is preferable to have a releasable negative electrode material (eighth configuration).

このようなリチウムを用いた電池では、リチウムが析出しないように、通常、正極側の電極の外形よりも負極側の電極の外形を大きく形成する。このような場合に、平面視で、正極側の電極の接続部における破断部分が負極側の電極の本体部の内方に位置していると、該正極側の電極の破断部分と負極側の電極との間で短絡が発生する。これに対し、上述の第１から第７の構成を適用することで、正極板の接続部が破断しれた場合でも、電池内での短絡発生を防止できる。   In such a battery using lithium, the outer shape of the negative electrode is generally larger than the outer shape of the positive electrode so that lithium does not precipitate. In such a case, in a plan view, when the fractured portion in the connection portion of the positive electrode is located inside the main body of the negative electrode, the fracture portion of the positive electrode and the negative electrode A short circuit occurs between the electrodes. On the other hand, by applying the first to seventh configurations described above, it is possible to prevent occurrence of a short circuit in the battery even when the connecting portion of the positive electrode plate is broken.

本発明の一実施形態にかかる積層型電池によれば、第１の電極の接続部に、平面視で第２の電極の外方に位置するように、破断部を設けた。これにより、積層型電池に衝撃が加わって第１の電極の接続部が破断部で破断した場合でも、該破断部と第２の電極との間で短絡が発生するのを防止できる。   According to the stacked battery of one embodiment of the present invention, the fracture portion is provided in the connection portion of the first electrode so as to be located outside the second electrode in plan view. Thereby, even when an impact is applied to the laminated battery and the connecting portion of the first electrode is broken at the broken portion, it is possible to prevent a short circuit from occurring between the broken portion and the second electrode.

また、前記破断部を、前記第１の電極板の接続部における本体部との接続部分で最も幅の狭い部分にしたり、該接続部に設けた切り欠き部によって構成したりすることで、該破断部でより確実に破断させることができる。これにより、電池内部での短絡発生をより確実に防止できる。   In addition, by making the fracture portion the narrowest portion of the connection portion of the connection portion of the first electrode plate with the main body portion, or by forming a notch portion provided in the connection portion, It can be more reliably broken at the broken portion. Thereby, the occurrence of a short circuit inside the battery can be more reliably prevented.

図１は、本発明の実施形態１にかかる扁平形電池の概略構成を示す断面図である。FIG. 1 is a cross-sectional view showing a schematic configuration of a flat battery according to Embodiment 1 of the present invention. 図２は、扁平形電池内の電極体の構造を断面で拡大して示す部分拡大断面図である。FIG. 2 is a partially enlarged cross-sectional view showing the structure of the electrode body in the flat battery in an enlarged view. 図３は、正極と負極とを重ね合わせた状態の平面図である。FIG. 3 is a plan view of a state in which the positive electrode and the negative electrode are superimposed. 図４は、セパレータによって覆われた正極の構成を示す平面図である。FIG. 4 is a plan view showing the configuration of the positive electrode covered with the separator. 図５は、負極の構成を示す平面図である。FIG. 5 is a plan view showing the configuration of the negative electrode. 図６は、正極と負極との位置関係を示す図である。FIG. 6 is a diagram illustrating a positional relationship between the positive electrode and the negative electrode. 図７は、実施形態２にかかるラミネート外装型電池の概略構成を示す斜視図である。FIG. 7 is a perspective view illustrating a schematic configuration of the laminated exterior battery according to the second embodiment. 図８は、図７におけるＶＩＩＩ−ＶＩＩＩ線断面図である。8 is a cross-sectional view taken along line VIII-VIII in FIG. 図９は、正極と負極との位置関係を示す図である。FIG. 9 is a diagram illustrating a positional relationship between the positive electrode and the negative electrode.

以下、図面を参照し、本発明の実施の形態を詳しく説明する。図中の同一または相当部分については同一の符号を付してその説明は繰り返さない。   Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals and description thereof will not be repeated.

［実施形態１］
（全体構成）
図１は、本発明の実施形態１にかかる積層型電池としての扁平形電池１の概略構成を示す断面図である。この扁平形電池１は、有底円筒状の外装缶としての負極缶１０と、該負極缶１０の開口を覆う封口缶としての正極缶２０と、負極缶１０の外周側と正極缶２０の外周側との間に配置されるガスケット３０と、負極缶１０及び正極缶２０の間に形成される空間内に収納される電極体４０（積層体）とを備えている。したがって、扁平形電池１は、負極缶１０と正極缶２０とを合わせることによって、全体が扁平なコイン状となる。扁平形電池１の負極缶１０及び正極缶２０の間に形成される空間内には、電極体４０以外に、非水電解液（図示省略）も封入されている。 [Embodiment 1]
(overall structure)
FIG. 1 is a cross-sectional view showing a schematic configuration of a flat battery 1 as a stacked battery according to Embodiment 1 of the present invention. The flat battery 1 includes a negative electrode can 10 as a bottomed cylindrical outer can, a positive electrode can 20 as a sealing can covering the opening of the negative electrode can 10, an outer peripheral side of the negative electrode can 10, and an outer periphery of the positive electrode can 20. A gasket 30 disposed between the electrode body 40 and the electrode body 40 (laminated body) housed in a space formed between the negative electrode can 10 and the positive electrode can 20. Therefore, the flat battery 1 is formed into a flat coin shape by combining the negative electrode can 10 and the positive electrode can 20 together. In the space formed between the negative electrode can 10 and the positive electrode can 20 of the flat battery 1, in addition to the electrode body 40, a non-aqueous electrolyte (not shown) is also enclosed.

負極缶１０は、ステンレスなどの金属材料からなり、プレス成形によって有底円筒状に形成されている。負極缶１０は、円形状の底部１１と、その外周に該底部１１と連続して形成される円筒状の周壁部１２とを備えている。この周壁部１２は、縦断面視（図１に図示した状態）で、底部１１の外周端からほぼ垂直に延びるように設けられている。負極缶１０は、正極缶２０との間にガスケット３０を挟んだ状態で、周壁部１２の開口端側が内側に折り曲げられて、該正極缶２０に対してかしめられている。なお、負極缶１０には、プレス成形によって折り曲げられた部分（例えば、底部１１と周壁部１２との間の部分など）に、それぞれ、曲面を有するＲ部分が形成されている。   The negative electrode can 10 is made of a metal material such as stainless steel and is formed into a bottomed cylindrical shape by press molding. The negative electrode can 10 includes a circular bottom portion 11 and a cylindrical peripheral wall portion 12 formed continuously with the bottom portion 11 on the outer periphery thereof. The peripheral wall portion 12 is provided so as to extend substantially vertically from the outer peripheral end of the bottom portion 11 in a longitudinal sectional view (the state illustrated in FIG. 1). In the state where the gasket 30 is sandwiched between the negative electrode can 10 and the positive electrode can 20, the opening end side of the peripheral wall portion 12 is bent inward and is crimped to the positive electrode can 20. The negative electrode can 10 is formed with R portions each having a curved surface in a portion bent by press molding (for example, a portion between the bottom portion 11 and the peripheral wall portion 12).

正極缶２０も、負極缶１０と同様、ステンレスなどの金属材料からなり、プレス成形によって有底円筒状に形成されている。正極缶２０は、負極缶１０の周壁部１２よりも外形が小さい円筒状の周壁部２２と、その一方の開口を塞ぐ円形状の平面部２１と、を有している。この周壁部２２も、負極缶１０と同様、縦断面視で、平面部２１に対してほぼ垂直に延びるように設けられている。周壁部２２には、平面部２１側の基端部２２ａに比べて径が段状に大きくなる拡径部２２ｂが形成されている。すなわち、周壁部２２には、基端部２２ａと拡径部２２ｂとの間に段部２２ｃが形成されている。図１に示すように、この段部２２ｃに対して、負極缶１０の周壁部１２の開口端側が折り曲げられてかしめられている。すなわち、負極缶１０は、その周壁部１２の開口端側が正極缶２０の段部２２ａに嵌合されている。なお、この正極缶２０も、プレス成形によって折り曲げられている部分（例えば、平面部２１と周壁部２２との間の部分や、段部２２ｃなど）には、それぞれ、曲面を有するＲ部分が形成されている。   Similarly to the negative electrode can 10, the positive electrode can 20 is also made of a metal material such as stainless steel, and is formed into a bottomed cylindrical shape by press molding. The positive electrode can 20 has a cylindrical peripheral wall portion 22 whose outer shape is smaller than that of the peripheral wall portion 12 of the negative electrode can 10 and a circular flat portion 21 that closes one of the openings. Similar to the negative electrode can 10, the peripheral wall portion 22 is also provided so as to extend substantially perpendicular to the plane portion 21 in a longitudinal sectional view. The peripheral wall portion 22 is formed with an enlarged diameter portion 22b whose diameter is increased stepwise compared to the base end portion 22a on the flat surface portion 21 side. That is, the peripheral wall portion 22 is formed with a step portion 22c between the base end portion 22a and the enlarged diameter portion 22b. As shown in FIG. 1, the open end side of the peripheral wall portion 12 of the negative electrode can 10 is bent and caulked with respect to the step portion 22c. That is, the negative electrode can 10 is fitted with the step 22 a of the positive electrode can 20 at the opening end side of the peripheral wall portion 12. In addition, the positive electrode can 20 is also formed with an R portion having a curved surface in a portion bent by press molding (for example, a portion between the flat portion 21 and the peripheral wall portion 22 or a step portion 22c). Has been.

ガスケット３０は、ポリプロピレン（ＰＰ）からなる。ガスケット３０は、負極缶１０の周壁部１２と正極缶２０の周壁部２２との間に挟みこまれるように、該正極缶２０の周壁部２２にモールド成形されている。なお、ガスケット３０の材料としては、ＰＰに限らず、ポリフェニレンサルファイド（ＰＰＳ）にオレフィン系エラストマーを含有した樹脂組成物や、ポリテトラフルオロエチレン（ＰＦＡ）、ポリアミド系樹脂などを用いてもよい。   The gasket 30 is made of polypropylene (PP). The gasket 30 is molded on the peripheral wall portion 22 of the positive electrode can 20 so as to be sandwiched between the peripheral wall portion 12 of the negative electrode can 10 and the peripheral wall portion 22 of the positive electrode can 20. The material of the gasket 30 is not limited to PP, and a resin composition containing an olefin elastomer in polyphenylene sulfide (PPS), polytetrafluoroethylene (PFA), a polyamide resin, or the like may be used.

電極体４０は、図２にも示すように、袋状のセパレータ４４（図２のみに図示）内に収容された概略円板状の正極４１（第１の電極）と、概略円板状の負極４６（第２の電極）と、を厚み方向に交互に複数、積層してなる。これにより、電極体４０は、全体として概略円柱状の形状を有している。また、電極体４０は、両端面が負極になるように、複数の正極４１及び負極４６が積層されている。なお、図１では、電極体４０を断面図ではなく、側面図として示している。   As shown in FIG. 2, the electrode body 40 includes a substantially disc-shaped positive electrode 41 (first electrode) housed in a bag-like separator 44 (shown only in FIG. 2), and a substantially disc-like electrode. A plurality of negative electrodes 46 (second electrodes) are alternately stacked in the thickness direction. Thereby, the electrode body 40 has a substantially cylindrical shape as a whole. In addition, the electrode body 40 has a plurality of positive electrodes 41 and negative electrodes 46 stacked so that both end faces are negative electrodes. In FIG. 1, the electrode body 40 is shown as a side view rather than a cross-sectional view.

正極４１は、正極活物質を含有する正極活物質層４２（正極材）を、アルミニウム等の金属箔製の正極集電体４３の両面にそれぞれ設けたものである。詳しくは、正極４１は、リチウムイオンを吸蔵・放出可能なリチウム含有酸化物である正極活物質、導電助剤及びバインダなどを含む正極合剤を、アルミニウム箔などからなる正極集電体４３上に塗布して乾燥させることによって形成される。正極活物質であるリチウム含有酸化物としては、例えば、ＬｉＣｏＯ２などのリチウムコバルト酸化物やＬｉＭｎ２Ｏ４などのリチウムマンガン酸化物、ＬｉＮｉＯ２などのリチウムニッケル酸化物等のリチウム複合酸化物を用いるのが好ましい。なお、正極活物質として、１種類の物質のみを用いてもよいし、２種類以上の物質を用いてもよい。また、正極活物質は、上述の物質のものに限られない。 The positive electrode 41 is obtained by providing positive electrode active material layers 42 (positive electrode material) containing a positive electrode active material on both surfaces of a positive electrode current collector 43 made of a metal foil such as aluminum. Specifically, the positive electrode 41 has a positive electrode mixture containing a positive electrode active material that is a lithium-containing oxide capable of occluding and releasing lithium ions, a conductive additive, and a binder on a positive electrode current collector 43 made of aluminum foil or the like. It is formed by applying and drying. As the lithium-containing oxide as the positive electrode active material, for example, a lithium composite oxide such as lithium cobalt oxide such as LiCoO 2 , lithium manganese oxide such as LiMn 2 O 4 , lithium nickel oxide such as LiNiO 2 is used. Is preferred. Note that only one type of material may be used as the positive electrode active material, or two or more types of materials may be used. Further, the positive electrode active material is not limited to those described above.

負極４６は、負極活物質を含有する負極活物質層４７（負極材）を、銅等の金属箔製の負極集電体４８の両面にそれぞれ設けたものである。詳しくは、負極４６は、リチウムイオンを吸蔵・放出可能な負極活物質、導電助剤及びバインダなどを含む負極合剤を、銅箔などからなる負極集電体４８上に塗布して乾燥させることによって形成される。負極活物質としては、例えば、リチウムイオンを吸蔵・放出可能な炭素材料（黒鉛類、熱分解炭素類、コークス類、ガラス状炭素類など）を用いるのが好ましい。負極活物質は、上述の物質のものに限られない。   The negative electrode 46 is provided with a negative electrode active material layer 47 (negative electrode material) containing a negative electrode active material on both surfaces of a negative electrode current collector 48 made of a metal foil such as copper. Specifically, the negative electrode 46 is formed by applying a negative electrode mixture containing a negative electrode active material capable of inserting and extracting lithium ions, a conductive additive and a binder onto a negative electrode current collector 48 made of copper foil or the like and drying it. Formed by. As the negative electrode active material, for example, it is preferable to use a carbon material (such as graphite, pyrolytic carbon, coke, or glassy carbon) that can occlude and release lithium ions. The negative electrode active material is not limited to those described above.

なお、略円柱状の電極体４０の軸方向両端に位置する負極は、それぞれ、負極集電体４８，４８が電極体４０の軸方向端部に位置するように、負極集電体４８の一面側のみに負極活物質層４７を有している。すなわち、略円柱状の電極体４０は、その両端に負極集電体４８，４８が露出している。この電極体４０の一方の負極集電体４８は、該電極体４０が負極缶１０と正極缶２０との間に配置された状態で、該負極缶１０の底部１１に当接する。電極体４０の他方の負極集電体４８は、絶縁シート４９を介して正極缶２０の平面部２１上に位置づけられる。   Note that the negative electrodes positioned at both ends in the axial direction of the substantially cylindrical electrode body 40 are arranged on one surface of the negative electrode current collector 48 so that the negative electrode current collectors 48 and 48 are positioned at the axial ends of the electrode body 40, respectively. The negative electrode active material layer 47 is provided only on the side. That is, the negative electrode current collectors 48 are exposed at both ends of the substantially cylindrical electrode body 40. One negative electrode current collector 48 of the electrode body 40 contacts the bottom 11 of the negative electrode can 10 in a state where the electrode body 40 is disposed between the negative electrode can 10 and the positive electrode can 20. The other negative electrode current collector 48 of the electrode body 40 is positioned on the flat surface portion 21 of the positive electrode can 20 via the insulating sheet 49.

セパレータ４４は、平面視で円形状に形成された袋状の部材であり、略円板状の正極４１を収納可能な大きさに形成されている。セパレータ４４は、絶縁性に優れたポリエチレン製の微多孔性薄膜によって構成されている。このように、セパレータ４４を微多孔性薄膜によって構成することで、リチウムイオンが該セパレータ４４を透過することができる。なお、セパレータ４４は、一枚の長方形状の微多孔性薄膜のシート材によって正極４１を包み込んで、該シート材の重なっている部分を熱溶着等によって接着することにより形成される。   The separator 44 is a bag-shaped member formed in a circular shape in plan view, and is formed in a size that can accommodate the substantially disc-shaped positive electrode 41. The separator 44 is constituted by a microporous thin film made of polyethylene having excellent insulating properties. Thus, by forming the separator 44 with a microporous thin film, lithium ions can pass through the separator 44. The separator 44 is formed by wrapping the positive electrode 41 with a single sheet of a rectangular microporous thin film and bonding the overlapping portions of the sheet material by heat welding or the like.

正極４１の正極集電体４３には、平面視で該正極集電体４３の外方に向かって延びる導電性の正極リード５１が一体形成されている。この正極リード５１の正極集電体４３側も、セパレータ４４によって覆われている。   The positive electrode current collector 43 of the positive electrode 41 is integrally formed with a conductive positive electrode lead 51 extending outward from the positive electrode current collector 43 in a plan view. The positive electrode current collector 43 side of the positive electrode lead 51 is also covered with the separator 44.

負極４６の負極集電体４８には、平面視で該負極集電体４８の外方に向かって延びる導電性の負極リード５２が一体形成されている。   The negative electrode current collector 48 of the negative electrode 46 is integrally formed with a conductive negative electrode lead 52 extending outward from the negative electrode current collector 48 in plan view.

図１に示すように、正極４１及び負極４６は、各正極４１の正極リード５１が一側に位置し、且つ、各負極４６の負極リード５２が該正極リード５１とは反対側に位置するように、積層される。これらの正極４１及び負極４６の各構成等について、詳しくは後述する。   As shown in FIG. 1, the positive electrode 41 and the negative electrode 46 are such that the positive electrode lead 51 of each positive electrode 41 is positioned on one side and the negative electrode lead 52 of each negative electrode 46 is positioned on the opposite side of the positive electrode lead 51. Is laminated. The configuration of each of the positive electrode 41 and the negative electrode 46 will be described later in detail.

上述のように複数の正極４１及び負極４６を厚み方向に積層した状態で、複数の正極リード５１は、先端側を厚み方向に重ね合わされて、超音波溶接等によって正極缶２０（固定部材、ケース部材）の平面部２１に接続される。これにより、複数の正極リード５１を介して複数の正極４１と正極缶２０の平面部２１とが電気的に接続される。一方、複数の負極リード５２も、先端側を厚み方向に重ね合わされて超音波溶接等によって互いに接続される。これにより、複数の負極リード５２を介して複数の負極４６が互いに電気的に接続される。   In the state where the plurality of positive electrodes 41 and the negative electrodes 46 are stacked in the thickness direction as described above, the plurality of positive electrode leads 51 are stacked in the thickness direction on the tip side, and the positive electrode can 20 (fixing member, case) is formed by ultrasonic welding or the like. Member). As a result, the plurality of positive electrodes 41 and the flat portion 21 of the positive electrode can 20 are electrically connected via the plurality of positive electrode leads 51. On the other hand, the plurality of negative electrode leads 52 are also connected to each other by ultrasonic welding or the like with the distal end side overlapped in the thickness direction. Thereby, the plurality of negative electrodes 46 are electrically connected to each other via the plurality of negative electrode leads 52.

上述のような構成の電極体４０では、正極４１と負極缶１０との接触、または、負極４６と正極缶２０との接触が生じる可能性がある。これに対し、本実施形態では、負極缶１０の周壁部１２よりも内方に位置付けられる正極缶２０の周壁部２２の内面に上述のガスケット３０が設けられている。このガスケット３０によって、電極体４０と負極缶１０との短絡の発生、及び、電極体４０と正極缶２０との短絡の発生がそれぞれ防止される。   In the electrode body 40 configured as described above, contact between the positive electrode 41 and the negative electrode can 10 or contact between the negative electrode 46 and the positive electrode can 20 may occur. On the other hand, in the present embodiment, the above-described gasket 30 is provided on the inner surface of the peripheral wall portion 22 of the positive electrode can 20 positioned inward of the peripheral wall portion 12 of the negative electrode can 10. The gasket 30 prevents the occurrence of a short circuit between the electrode body 40 and the negative electrode can 10 and the occurrence of a short circuit between the electrode body 40 and the positive electrode can 20.

（正極及び負極の構成）
図３から図６に正極４１及び負極４６の構成を示す。図３は、電極体４０において、負極４６上にセパレータ４４で覆われた正極４１を重ね合わせた状態の上面図である。図４は、セパレータ４４によって覆われた正極４１の平面図であり、図５は負極４６の平面図である。また、図６は、負極４６と正極５１との配置関係を示す図である。 (Configuration of positive electrode and negative electrode)
FIGS. 3 to 6 show the configurations of the positive electrode 41 and the negative electrode 46. FIG. 3 is a top view of the electrode body 40 in a state where the positive electrode 41 covered with the separator 44 is superimposed on the negative electrode 46. FIG. 4 is a plan view of the positive electrode 41 covered with the separator 44, and FIG. 5 is a plan view of the negative electrode 46. FIG. 6 is a diagram showing the arrangement relationship between the negative electrode 46 and the positive electrode 51.

図４に示すように、正極４１は、円盤の一部を切り欠いた形状の正極本体部４５（本体部）と、該正極本体部４５から外方に向かって延びる正極リード５１（接続部）とを備えている。すなわち、正極本体部４５は、正極集電体４３上に正極活物質層４２が設けられたものである。この正極集電体４３に正極リード５１が一体形成されている。さらに、正極本体部４５及び正極リード５１の一部は、既述のとおり、セパレータ４４によって覆われている。   As shown in FIG. 4, the positive electrode 41 includes a positive electrode main body portion 45 (main body portion) having a shape in which a part of a disk is cut out, and a positive electrode lead 51 (connection portion) extending outward from the positive electrode main body portion 45. And. In other words, the positive electrode main body 45 is obtained by providing the positive electrode active material layer 42 on the positive electrode current collector 43. A positive electrode lead 51 is integrally formed with the positive electrode current collector 43. Furthermore, the positive electrode main body 45 and a part of the positive electrode lead 51 are covered with the separator 44 as described above.

正極リード５１の正極本体部４５との接続部分には、Ｒ部４３ａが形成されている。このＲ部４３ａを設けることによって、正極リード５１の正極本体部４５との接続部分における応力集中を緩和することができる。さらに、詳しくは後述するが、図６に示すように、正極４１のＲ部４３ａは、正極４１と負極４６とを重ね合わせた状態で、Ｒ部４３ａの正極リード５１側の端が平面視で負極４６の外方に位置するように、設けられている。   An R portion 43 a is formed at a portion where the positive electrode lead 51 is connected to the positive electrode main body 45. By providing the R portion 43a, stress concentration at the connection portion of the positive electrode lead 51 with the positive electrode main body 45 can be reduced. Further, as will be described in detail later, as shown in FIG. 6, the R portion 43 a of the positive electrode 41 is in a state where the positive electrode 41 and the negative electrode 46 are overlapped, and the end of the R portion 43 a on the positive electrode lead 51 side in plan view. It is provided so as to be located outside the negative electrode 46.

図５に示すように、負極４６は、上述の正極４１と同様、円盤の一部を切り欠いた形状の負極本体部５０（本体部）と、該負極本体部５０から外方に向かって延びる負極リード５２（接続部）とを備えている。この負極本体部５０も、上述の正極本体部４５と同様、負極集電体４８上に負極活物質層４７が設けられたものである。そして、負極リード５２も、負極集電体４８に一体形成されている。   As shown in FIG. 5, the negative electrode 46, like the positive electrode 41 described above, extends outwardly from the negative electrode main body 50 (main body) having a shape in which a part of the disk is cut out. And a negative electrode lead 52 (connection portion). Similarly to the positive electrode main body 45 described above, the negative electrode main body 50 also has a negative electrode active material layer 47 provided on a negative electrode current collector 48. The negative electrode lead 52 is also integrally formed with the negative electrode current collector 48.

負極本体部５０は、上述のようにセパレータ４４によって覆われた状態の正極本体部４５とほぼ同じ大きさになるように形成されている。すなわち、負極本体部５０は、正極本体部４５よりも大きい外形を有している。なお、図５及び図６において、負極本体部５０と負極リード５２との間に記載されているラインは、負極集電体４８上に形成された負極活物質層４７の外周の一部を示している。同様に、図６において、正極本体部４５と正極リード５１との間に記載されているラインは、正極集電体４３上に形成された正極活物質層４２の外周の一部を示している。   The negative electrode main body 50 is formed to have substantially the same size as the positive electrode main body 45 covered with the separator 44 as described above. That is, the negative electrode main body 50 has a larger outer shape than the positive electrode main body 45. 5 and 6, a line described between the negative electrode main body 50 and the negative electrode lead 52 indicates a part of the outer periphery of the negative electrode active material layer 47 formed on the negative electrode current collector 48. ing. Similarly, in FIG. 6, a line described between the positive electrode main body 45 and the positive electrode lead 51 indicates a part of the outer periphery of the positive electrode active material layer 42 formed on the positive electrode current collector 43. .

図３に示すように、正極４１及び負極４６は、正極リード５１と負極リード５２とが逆方向に延びるように正極本体部４５と負極本体部５０とが重ねられることにより、厚み方向に積層されている。これにより、概略円柱状の電極体４０と、該電極体４０からそれぞれ逆方向に延びるリード群６１，６２とが形成される（図１〜図３参照）。リード群６１，６２のうち、正極リード５１からなるリード群６１は、超音波溶接等によって、互いに接続されるとともに正極缶２０に接続される。一方、負極リード５２からなるリード群６２は、超音波溶接等によって互いに接続される。これにより、電極体４０は、負極４６同士が電気的に接続されるとともに、正極４１も正極リード５１を介して正極缶２０に電気的に接続される。   As shown in FIG. 3, the positive electrode 41 and the negative electrode 46 are laminated in the thickness direction by overlapping the positive electrode main body 45 and the negative electrode main body 50 so that the positive electrode lead 51 and the negative electrode lead 52 extend in opposite directions. ing. As a result, a substantially cylindrical electrode body 40 and lead groups 61 and 62 extending in opposite directions from the electrode body 40 are formed (see FIGS. 1 to 3). Of the lead groups 61 and 62, the lead group 61 including the positive electrode lead 51 is connected to the positive electrode can 20 and to the positive electrode can 20 by ultrasonic welding or the like. On the other hand, the lead group 62 composed of the negative electrode lead 52 is connected to each other by ultrasonic welding or the like. Thereby, in the electrode body 40, the negative electrodes 46 are electrically connected to each other, and the positive electrode 41 is also electrically connected to the positive electrode can 20 via the positive electrode lead 51.

上述の構成により、扁平形電池１内での正極４１と負極４６との間のリチウムイオンの移動によって、該扁平形電池１内で充放電を行うことができる。しかも、上述のように、平面視で、負極本体部５０の外形を正極本体部４５の外形よりも大きくすることで、負極４６にリチウムイオンを吸収しやすくすることができる。これにより、負極４６上にリチウムが析出するのを防止することができ、リチウムの析出による正極４１と負極４６との短絡発生を防止できる。   With the above configuration, charging and discharging can be performed in the flat battery 1 by the movement of lithium ions between the positive electrode 41 and the negative electrode 46 in the flat battery 1. In addition, as described above, by making the outer shape of the negative electrode main body portion 50 larger than the outer shape of the positive electrode main body portion 45 in plan view, the negative electrode 46 can easily absorb lithium ions. Thereby, it is possible to prevent lithium from being deposited on the negative electrode 46, and it is possible to prevent occurrence of a short circuit between the positive electrode 41 and the negative electrode 46 due to lithium deposition.

ところで、本実施形態のように正極４１の正極リード５１が正極缶２０に接続された構成において、落下等によって扁平形電池１全体に大きな衝撃が加わると、正極リード５１が大きな力を受けて破断する場合がある。このとき、上述のとおり、正極リード５１の正極本体部４５との接続部分にはＲ部分が設けられているため、該接続部分で最も応力が大きくなる部分は、幅が最も狭くなるＲ部分の正極リード５１側の端になる。   By the way, in the configuration in which the positive electrode lead 51 of the positive electrode 41 is connected to the positive electrode can 20 as in the present embodiment, if a large impact is applied to the entire flat battery 1 due to dropping or the like, the positive electrode lead 51 receives a large force and breaks. There is a case. At this time, as described above, since the R portion is provided in the connection portion of the positive electrode lead 51 with the positive electrode main body 45, the portion where the stress is the largest in the connection portion is the R portion where the width is the narrowest. This is the end on the positive electrode lead 51 side.

ここで、上述のように、平面視で負極本体部５０の外形が正極本体部４５の外形よりも大きいと、正極リード５１が負極本体部５０の内方から外方に向かって突出する。この構成において、前記接続部分で最も応力が大きい部分（Ｒ部分の正極リード５１側の端）が平面視で負極本体部５０の内方に位置している場合、上述のような正極リード５１の破断が生じると、破断部分が負極４６に接触する可能性がある。すなわち、上述のとおり、正極４１はセパレータ４４によって覆われているものの、正極リード５１の破断した部分がセパレータ４４を突き抜けて負極４６に接触し、該負極４６との間で短絡を生じる可能性がある。   Here, as described above, when the outer shape of the negative electrode main body portion 50 is larger than the outer shape of the positive electrode main body portion 45 in plan view, the positive electrode lead 51 protrudes from the inner side of the negative electrode main body portion 50 toward the outer side. In this configuration, when the portion having the largest stress in the connection portion (the end of the R portion on the positive electrode lead 51 side) is located inward of the negative electrode main body 50 in plan view, When the rupture occurs, the rupture portion may come into contact with the negative electrode 46. That is, as described above, although the positive electrode 41 is covered with the separator 44, the broken portion of the positive electrode lead 51 may penetrate the separator 44 and contact the negative electrode 46, thereby causing a short circuit with the negative electrode 46. is there.

これに対し、本実施形態では、図６に示すように、正極４１と負極４６とを重ね合わせた状態で、正極リード５１の破断箇所Ｘ（破断部、正極リード５１の正極本体部４５との接続部分において幅が最も狭くなる部分）が平面視で負極本体部５０の外方に位置するように、正極４１のＲ部４３ａを形成する。なお、本実施形態の場合、破断箇所Ｘは、Ｒ部４３ａにおいて最も応力が大きくなる正極リード５１側の端、すなわち、Ｒ部４３ａの曲線から直線に変わる部分である。   On the other hand, in the present embodiment, as shown in FIG. 6, in the state where the positive electrode 41 and the negative electrode 46 are overlapped, the breakage point X of the positive electrode lead 51 (the broken portion, the positive electrode main body 45 of the positive electrode lead 51 and The R portion 43a of the positive electrode 41 is formed so that the narrowest portion of the connecting portion is located outside the negative electrode main body 50 in plan view. In the case of the present embodiment, the breakage point X is an end on the positive electrode lead 51 side where the stress is greatest in the R portion 43a, that is, a portion that changes from a curve of the R portion 43a to a straight line.

上述のように、正極リード５１の破断箇所Ｘを負極本体部５０の外方に位置付けることにより、該正極リード５１が破断箇所Ｘで破断した場合でも、その破断部分が負極４６に接触するのを防止できる。これにより、正極リード５１の破断によって、扁平形電池１の内部で短絡が生じるのを防止できる。   As described above, by positioning the broken portion X of the positive electrode lead 51 outside the negative electrode main body 50, even when the positive electrode lead 51 is broken at the broken portion X, the broken portion is in contact with the negative electrode 46. Can be prevented. Thereby, it is possible to prevent a short circuit from occurring inside the flat battery 1 due to the breakage of the positive electrode lead 51.

（検証試験）
上述のような構成を有する扁平形電池において、衝撃を加えた場合でも正極及び負極の間で短絡が発生しないことを検証試験によって確認した。以下でその検証試験の概要及び試験結果について説明する。 (Verification test)
In the flat battery having the above-described configuration, it was confirmed by a verification test that no short circuit occurred between the positive electrode and the negative electrode even when an impact was applied. The outline of the verification test and the test results will be described below.

検証試験では、上述のような構成を有する扁平形電池を、１．９ｍの高さから１０回、落下させた後、扁平形電池に発熱が生じたかどうかを確認した。この検証試験で用いる扁平形電池は、総重量が約３ｇで、正極集電体の直径が約１５ｍｍの電池である。また、扁平形電池の正極リードと正極本体部との間に形成されるＲ部の曲率半径は、Ｒ＝１．５ｍｍである。この曲率半径は、本検証試験で用いた扁平形電池において、構造上、最大限確保できる曲率半径で且つ正極リードをリード群として正極缶に溶接する際に容易に該正極リードを加工できる曲率半径である。   In the verification test, the flat battery having the above-described configuration was dropped 10 times from a height of 1.9 m, and then it was confirmed whether or not heat was generated in the flat battery. The flat battery used in this verification test is a battery having a total weight of about 3 g and a positive electrode current collector having a diameter of about 15 mm. Further, the radius of curvature of the R portion formed between the positive electrode lead and the positive electrode main body portion of the flat battery is R = 1.5 mm. This radius of curvature is the radius of curvature that can be secured to the maximum extent in the structure of the flat battery used in this verification test, and the radius of curvature that can easily process the positive electrode lead when welding the positive electrode lead as a lead group to the positive electrode can. It is.

なお、この検証試験では、扁平形電池１をプラスチックタイル上に落下させる。このとき、扁平形電池１が受ける衝撃荷重は、約１７Ｎである。   In this verification test, the flat battery 1 is dropped on a plastic tile. At this time, the impact load received by the flat battery 1 is about 17N.

１００個以上の扁平形電池を用いて上述の検証試験を行ったが、いずれの扁平形電池でも温度が４０度以上になるような発熱はなかった。これらの扁平形電池を分解してみると、いずれも正極リードが破断していた。これらのことから、上述の構成の扁平形電池に衝撃を加えて正極リードが破断した場合でも、正極と負極との間で短絡が発生していないことが分かる。   The above-described verification test was performed using 100 or more flat batteries, but none of the flat batteries generated heat at a temperature of 40 degrees or more. When these flat batteries were disassembled, the positive electrode lead was broken in all cases. From these facts, it is understood that no short circuit occurs between the positive electrode and the negative electrode even when an impact is applied to the flat battery having the above-described configuration and the positive electrode lead is broken.

なお、比較のために、正極リードの破断箇所が平面視で負極本体部の内方に位置している構成においても、上述の検証試験と同様の試験を行った。このような構成の扁平形電池では、衝撃を加えた後に温度が４０度以上になる発熱が生じた。これにより、正極リードの破断箇所が平面視で負極本体部の内方に位置している構成では、電池内部で短絡が生じていることが分かる。この比較例において、正極リードと正極本体部との間に形成されるＲ部の曲率半径は、Ｒ＝０．５ｍｍである。なお、本検証試験で用いた扁平形電池の場合、正極リードの破断箇所が平面視で負極の外方に位置するようなＲ部の曲率半径は、Ｒ＝０．７ｍｍ以上である。   For comparison, a test similar to the above-described verification test was performed even in a configuration in which the fractured portion of the positive electrode lead was positioned inward of the negative electrode main body in a plan view. In the flat battery having such a configuration, heat was generated at a temperature of 40 ° C. or higher after an impact was applied. Thus, it can be seen that a short circuit occurs in the battery in the configuration in which the broken portion of the positive electrode lead is located inward of the negative electrode main body in a plan view. In this comparative example, the radius of curvature of the R portion formed between the positive electrode lead and the positive electrode main body is R = 0.5 mm. In the case of the flat battery used in this verification test, the radius of curvature of the R portion where the broken portion of the positive electrode lead is located outside the negative electrode in plan view is R = 0.7 mm or more.

（実施形態１の効果）
以上より、この実施形態では、正極４１と負極４６とを交互に重ね合わせる構成において、該正極４１の正極リード５１の切断箇所Ｘが平面視で負極４１の負極本体部５０の外方に位置するように、正極リード５１の正極本体部４５との接続部分にＲ部４３ａを形成した。これにより、扁平形電池１に衝撃が加わって正極リード５１が破断箇所Ｘで破断した場合でも、その破断部分が負極４６に接触しないため、正極４１と負極４６との間で短絡が発生するのを防止できる。 (Effect of Embodiment 1)
As described above, in this embodiment, in the configuration in which the positive electrode 41 and the negative electrode 46 are alternately overlapped, the cut portion X of the positive electrode lead 51 of the positive electrode 41 is located outside the negative electrode main body 50 of the negative electrode 41 in plan view. As described above, the R portion 43 a is formed at the connection portion between the positive electrode lead 51 and the positive electrode main body 45. Thereby, even when an impact is applied to the flat battery 1 and the positive electrode lead 51 breaks at the breakage point X, the breakage portion does not come into contact with the negative electrode 46, so that a short circuit occurs between the positive electrode 41 and the negative electrode 46. Can be prevented.

［実施形態２］
図７に、実施形態２にかかる積層型電池としてのラミネート外装型電池１００の概略構成を示す。図８は、ラミネート外装型電池１００の概略構成を示す断面図である。このラミネート外装型電池１００は、発電体として機能する平板状の積層体１１０がラミネートフィルム外装体１２０（シート部材）によって覆われた略平板状の二次電池である。なお、本実施形態にかかるラミネート外装型電池１００は、例えば、厚み方向に複数、並べられて互いに電気的に接続されることにより、図示しない電池モジュールを構成する。 [Embodiment 2]
FIG. 7 shows a schematic configuration of a laminated exterior battery 100 as a stacked battery according to the second embodiment. FIG. 8 is a cross-sectional view illustrating a schematic configuration of the laminated exterior battery 100. This laminated exterior battery 100 is a substantially planar secondary battery in which a planar laminate 110 that functions as a power generator is covered with a laminate film exterior 120 (sheet member). Note that, for example, a plurality of laminated exterior batteries 100 according to the present embodiment are arranged in the thickness direction and electrically connected to each other, thereby constituting a battery module (not shown).

図７及び図８に示すように、ラミネート外装型電池１００は、シート状の正極１１１（第１の電極）及び負極１１２（第２の電極）がセパレータ１１３を間に挟んで交互に積層された積層体１１０と、該積層体１１０を覆うラミネートフィルム外装体１２０と、積層体１１０の正極１１１及び負極１１２にそれぞれ接続される正極外部端子１３１及び負極外部端子１３２（外部端子）と、を備えている。なお、ラミネート外装型電池１００の内部には、非水電解質も封入されている。   As shown in FIGS. 7 and 8, the laminate-type battery 100 includes sheet-like positive electrodes 111 (first electrodes) and negative electrodes 112 (second electrodes) that are alternately stacked with separators 113 therebetween. A laminate 110, a laminate film outer package 120 covering the laminate 110, and a positive external terminal 131 and a negative external terminal 132 (external terminal) connected to the positive electrode 111 and the negative electrode 112 of the laminate 110, respectively. Yes. Note that a nonaqueous electrolyte is also enclosed inside the laminate-cased battery 100.

正極１１１は、リチウムイオンを吸蔵・放出可能なリチウム含有酸化物である正極活物質、導電助剤及びバインダなどを含む正極合剤（正極材）を、アルミニウム箔などからなる正極集電体上に塗布して乾燥させることによって形成される。正極活物質であるリチウム含有酸化物としては、例えば、ＬｉＣｏＯ２などのリチウムコバルト酸化物やＬｉＭｎ２Ｏ４などのリチウムマンガン酸化物、ＬｉＮｉＯ２などのリチウムニッケル酸化物等のリチウム複合酸化物を用いるのが好ましい。なお、正極活物質として、１種類の物質のみを用いてもよいし、２種類以上の物質を用いてもよい。また、正極活物質は、上述の物質のものに限られない。 The positive electrode 111 has a positive electrode mixture (positive electrode material) containing a positive electrode active material that is a lithium-containing oxide capable of occluding and releasing lithium ions, a conductive additive, and a binder on a positive electrode current collector made of aluminum foil or the like. It is formed by applying and drying. As the lithium-containing oxide as the positive electrode active material, for example, a lithium composite oxide such as lithium cobalt oxide such as LiCoO 2 , lithium manganese oxide such as LiMn 2 O 4 , lithium nickel oxide such as LiNiO 2 is used. Is preferred. Note that only one type of material may be used as the positive electrode active material, or two or more types of materials may be used. Further, the positive electrode active material is not limited to those described above.

正極１１１は、正極本体部１１５（本体部）と、該正極本体部１１５を外部端子１３１に接続するための正極リード１３３（接続部）とを備えている。   The positive electrode 111 includes a positive electrode main body portion 115 (main body portion) and a positive electrode lead 133 (connection portion) for connecting the positive electrode main body portion 115 to the external terminal 131.

負極１１２は、リチウムイオンを吸蔵・放出可能な負極活物質、導電助剤及びバインダなどを含む負極合剤（負極材）を、銅箔などからなる負極集電体上に塗布して乾燥させることによって形成される。負極活物質としては、例えば、リチウムイオンを吸蔵・放出可能な炭素材料（黒鉛類、熱分解炭素類、コークス類、ガラス状炭素類など）を用いるのが好ましい。なお、負極活物質は、上述の物質のものに限られない。   The negative electrode 112 is formed by applying a negative electrode mixture (negative electrode material) containing a negative electrode active material capable of inserting and extracting lithium ions, a conductive additive and a binder onto a negative electrode current collector made of copper foil or the like, and drying it. Formed by. As the negative electrode active material, for example, it is preferable to use a carbon material (such as graphite, pyrolytic carbon, coke, or glassy carbon) that can occlude and release lithium ions. Note that the negative electrode active material is not limited to that described above.

負極１１２は、負極本体部１１６（本体部）と、該負極本体部１１６を負極外部端子１３２に接続するための負極リード１３４とを備えている。   The negative electrode 112 includes a negative electrode main body portion 116 (main body portion) and a negative electrode lead 134 for connecting the negative electrode main body portion 116 to the negative electrode external terminal 132.

正極外部端子１３１及び負極外部端子１３２は、その一端側が、ラミネートフィルム外装体１２０によって挟み込まれて該ラミネートフィルム外装体１２０と一体化される一方、他端側がラミネートフィルム外装体１２０の外方に向かって突出している。すなわち、図７に示すように、これらの正極外部端子１３１及び負極外部端子１３２は、互いに離間した位置で、ラミネートフィルム外装体１２０の外方へ同じ方向に向かって突出している。特に図示しないが、例えば、正極外部端子１３１及び負極外部端子１３２は、それぞれ、外部の接続端子（固定部材）に接続固定されている。   One end of each of the positive electrode external terminal 131 and the negative electrode external terminal 132 is sandwiched by the laminate film exterior body 120 and integrated with the laminate film exterior body 120, while the other end side faces the outside of the laminate film exterior body 120. Protruding. That is, as shown in FIG. 7, the positive electrode external terminal 131 and the negative electrode external terminal 132 protrude toward the outside of the laminate film exterior body 120 in the same direction at positions separated from each other. Although not particularly illustrated, for example, the positive external terminal 131 and the negative external terminal 132 are each connected and fixed to an external connection terminal (fixing member).

セパレータ１１３は、例えば、ポリエチレンやポリプロピレン、ポリエチレンとポリプロピレンとの融合体、ポリエチレンテレフタレートやポリブチレンテレフタレートなどによって構成された多孔質フィルム、または、セルロースなどからなる不織布によって形成される。このセパレータ１１３は、正極１１１の両面を挟み込んだ状態で、外周側が溶着されたものである。すなわち、セパレータ１１３は、正極１１１を包み込むように形成されている。   The separator 113 is made of, for example, polyethylene, polypropylene, a fusion of polyethylene and polypropylene, a porous film made of polyethylene terephthalate, polybutylene terephthalate, or the like, or a nonwoven fabric made of cellulose or the like. This separator 113 is welded on the outer peripheral side with both surfaces of the positive electrode 111 being sandwiched. That is, the separator 113 is formed so as to enclose the positive electrode 111.

ラミネートフィルム外装体１２０は、アルミニウム製の金属箔の一面側がナイロンで覆われ、且つ、他面側がポリプロピレンで覆われた材料からなる。すなわち、ラミネートフィルム外装体１２０は、アルミニウムをナイロン及びポリプロピレンでラミネートした材料からなる。これにより、ラミネートフィルム外装体１２０は、ラミネートフィルム外装体１２０同士を重ね合わせた状態で加熱しながら圧力を加えることによって、互いに接着される。   The laminate film exterior body 120 is made of a material in which one side of an aluminum metal foil is covered with nylon and the other side is covered with polypropylene. That is, the laminate film exterior body 120 is made of a material obtained by laminating aluminum with nylon and polypropylene. Thereby, the laminate film exterior body 120 is mutually adhere | attached by applying a pressure, heating in the state which laminated | stacked laminate film exterior body 120 mutually.

本実施形態のラミネートフィルム外装体１２０は、略長方形状に形成されている。このラミネートフィルム外装体１２０によって積層体１１０を包み込んだ状態で、該ラミネートフィルム外装体１２０の外周側同士を接着することにより、膨出部１００ａ及びシール部１００ｂが形成される。すなわち、ラミネートフィルム外装体１２０が積層体１１０を覆うことにより膨出部１００ａが形成され、該膨出部１００ａの三方でラミネートフィルム外装体１２０同士を接着することにより該膨出部１００ａを囲むようにシール部１００ｂが形成される。   The laminate film exterior body 120 of this embodiment is formed in a substantially rectangular shape. In a state where the laminate 110 is wrapped by the laminate film exterior body 120, the outer peripheral sides of the laminate film exterior body 120 are bonded to each other, whereby the bulging portion 100a and the seal portion 100b are formed. That is, the bulging portion 100a is formed by covering the laminate 110 with the laminate film outer package 120, and the bulging portion 100a is surrounded by adhering the laminate film outer package 120 to each other at three sides of the bulged portion 100a. The seal portion 100b is formed.

ここで、ラミネートフィルム外装体１２０と、その外方に一部が突出する正極外部端子１３１及び負極外部端子１３２との間には、それぞれ、接着層１３１ａ，１３２ａが設けられている。これらの接着層１３１ａ，１３２ａを設けることにより、ラミネートフィルム外装体１２０と正極外部端子１３１及び負極外部端子１３２とをそれぞれ強固に接着することができる。   Here, adhesive layers 131a and 132a are provided between the laminate film outer package 120 and the positive electrode external terminal 131 and the negative electrode external terminal 132, respectively, partially protruding outward. By providing these adhesive layers 131a and 132a, the laminate film outer package 120, the positive external terminal 131, and the negative external terminal 132 can be firmly bonded to each other.

（リードの接続構造）
図９に、正極１１１と負極１１２との配置関係を示す。この図９において、一点鎖線は、ラミネートフィルム外装体１２０の外形を示していて、破線は、正極１１１の正極本体部１１５の外形を示している。 (Lead connection structure)
FIG. 9 shows an arrangement relationship between the positive electrode 111 and the negative electrode 112. In FIG. 9, the alternate long and short dash line indicates the outer shape of the laminate film outer package 120, and the broken line indicates the outer shape of the positive electrode main body 115 of the positive electrode 111.

セパレータ１１３によって覆われた正極１１１の正極本体部１１５と、負極本体部１１６とは平面視で略同一の大きさに形成されている。すなわち、図９において、セパレータ１１３の外形と負極本体部１１６の外形とはほぼ同じ大きさである。したがって、平面視で、正極本体部１１５の外形は、負極本体部１１６の外形よりも小さい。これにより、実施形態１の構成と同様、負極１１２側でリチウムが析出するのを防止することができ、該負極１１２と正極１１１との間で短絡が発生するのを防止できる。   The positive electrode main body 115 and the negative electrode main body 116 of the positive electrode 111 covered with the separator 113 are formed in substantially the same size in plan view. That is, in FIG. 9, the outer shape of the separator 113 and the outer shape of the negative electrode main body 116 are approximately the same size. Therefore, the outer shape of the positive electrode main body 115 is smaller than the outer shape of the negative electrode main body 116 in a plan view. Thereby, like the structure of Embodiment 1, it can prevent that lithium precipitates on the negative electrode 112 side, and can prevent that a short circuit generate | occur | produces between this negative electrode 112 and the positive electrode 111. FIG.

正極リード１３３は、既述のように正極外部端子１３１が外部の接続部材に接続されるため、該正極外部端子１３１に接続される一端側で固定された状態になる。   As described above, since the positive electrode external terminal 131 is connected to an external connection member as described above, the positive electrode lead 133 is fixed at one end connected to the positive electrode external terminal 131.

この実施形態２においても、上述の実施形態１と同様、正極リード１３３の正極本体部１１５との接続部分に、応力集中を緩和するためのＲ部１１１ａが設けられている。なお、このＲ部１１１ａは、ラミネート外装型電池１００に衝撃が加わった際の正極リード１３３の破断箇所Ｘ（破断部）が、平面視で負極本体部１１６の外方に位置するように形成されている。この破断箇所Ｘは、実施形態１と同様、Ｒ部１１１ａの正極リード１３３側の端、すなわち、正極リード１３３の正極本体部１１５との接続部分で最も幅が狭くなる部分（Ｒ部１１１ａの曲線から直線になる部分）である。また、この破断箇所Ｘが、ラミネート外装型電池１００に衝撃が加わった場合に、正極リード１３３で最も応力が大きくなる部分である。   Also in the second embodiment, as in the first embodiment described above, the R portion 111a for relaxing stress concentration is provided at the connection portion between the positive electrode lead 133 and the positive electrode main body 115. The R portion 111a is formed such that the broken portion X (broken portion) of the positive electrode lead 133 when an impact is applied to the laminated exterior battery 100 is located outside the negative electrode main body portion 116 in a plan view. ing. As in the first embodiment, the fractured portion X is the end of the R portion 111a on the positive electrode lead 133 side, that is, the portion having the narrowest width at the connection portion of the positive electrode lead 133 with the positive electrode main body 115 (the curve of the R portion 111a). To the straight line). In addition, the fracture portion X is a portion where the stress is greatest in the positive electrode lead 133 when an impact is applied to the laminated exterior battery 100.

これにより、実施形態１と同様、正極リード１３３が破断箇所Ｘで破断した場合に、その破断部分が負極１１２に接触して短絡を生じるのを防止できる。   Thereby, similarly to Embodiment 1, when the positive electrode lead 133 breaks at the breakage point X, it is possible to prevent the broken portion from coming into contact with the negative electrode 112 and causing a short circuit.

なお、負極リード１３４の負極本体部１１６との接続部分にも、応力集中を緩和するためのＲ部１１２ａが設けられている。   Note that an R portion 112a for relaxing stress concentration is also provided at a portion where the negative electrode lead 134 is connected to the negative electrode main body 116.

（実施形態２の効果）
以上より、この実施形態によれば、ラミネート外装型電池１００において、正極リード１３３の正極本体部１１５との接続部分に、該正極リード１３３の破断箇所Ｘが平面視で負極１１２の外方に位置するようにＲ部１１１ａを設けた。これにより、ラミネート外装型電池１００に衝撃が加わって正極リード１３３が破断箇所Ｘで破断した場合でも、その破断部分が負極１１２に接触するのを防止することができる。これにより、正極リード１３３の破断によって正極１１１と負極１１２との間で短絡が発生するのを防止できる。 (Effect of Embodiment 2)
As described above, according to this embodiment, in the laminate-type battery 100, the breakage point X of the positive electrode lead 133 is positioned outside the negative electrode 112 in a plan view at the connection portion of the positive electrode lead 133 with the positive electrode main body 115. The R portion 111a is provided as described above. Thereby, even when an impact is applied to the laminate-type battery 100 and the positive electrode lead 133 breaks at the breakage point X, the breakage portion can be prevented from coming into contact with the negative electrode 112. Thereby, it is possible to prevent a short circuit from occurring between the positive electrode 111 and the negative electrode 112 due to the breakage of the positive electrode lead 133.

（その他の実施形態）
以上、本発明の実施の形態を説明したが、上述した実施の形態は本発明を実施するための例示に過ぎない。よって、上述した実施の形態に限定されることなく、その趣旨を逸脱しない範囲内で上述した実施の形態を適宜変形して実施することが可能である。 (Other embodiments)
While the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and the above-described embodiment can be appropriately modified and implemented without departing from the spirit of the invention.

前記各実施形態では、正極リード５１，１３３の破断箇所Ｘを、該正極リード５１，１３３における正極４１，１１１との接続部分で最も幅の狭い部分としている。しかしながら、正極リードの破断箇所に、例えば切り欠き部や空洞部を設けて、該破断箇所で破断しやすいようにしてもよい。切り欠き部を設ける場合には、例えば、正極リードの幅方向端部の一方または両方に切り欠き部を設ければよい。また、空洞部を設ける場合には、例えば、破断箇所の正極リード内方に空洞を設ければよい。   In each of the embodiments described above, the breakage point X of the positive electrode leads 51 and 133 is the narrowest part of the positive electrode leads 51 and 133 connected to the positive electrodes 41 and 111. However, for example, a notch portion or a hollow portion may be provided at a breakage point of the positive electrode lead so that the breakage is easily caused at the breakage point. When providing the notch, for example, the notch may be provided at one or both of the end portions in the width direction of the positive electrode lead. Moreover, what is necessary is just to provide a cavity in the positive electrode lead inside of a fracture | rupture location, for example, when providing a cavity part.

前記各実施形態では、各電池をリチウムイオン電池として構成している。しかしながら、各電池は、リチウムイオン電池以外の電池であってもよい。この場合には、負極の外形を正極よりも大きくする必要がないため、負極と正極とを同じ大きさの外形にすればよい。また、このようにリチウムイオン電池以外の電池の場合には、負極リードを固定側として、該負極リードに前記各実施形態の構成を適用してもよい。   In the above embodiments, each battery is configured as a lithium ion battery. However, each battery may be a battery other than a lithium ion battery. In this case, since it is not necessary to make the outer shape of the negative electrode larger than that of the positive electrode, the negative electrode and the positive electrode may have the same size. Further, in the case of a battery other than the lithium ion battery as described above, the configuration of each of the above embodiments may be applied to the negative electrode lead with the negative electrode lead as the fixed side.

前記各実施形態では、正極リード５１，１３３の正極本体部４５，１１５との接続部分にＲ部４３ａ，１１１ａを設けている。しかしながら、接続部分の応力集中を緩和できるように、正極リード５１，１３３側に向かって該接続部分の幅が徐々に狭くなるような形状であれば、他の形状であってもよい。   In each of the embodiments described above, the R portions 43a and 111a are provided at the connection portions of the positive electrode leads 51 and 133 with the positive electrode main body portions 45 and 115, respectively. However, other shapes may be used as long as the width of the connection portion gradually narrows toward the positive electrode leads 51 and 133 so that the stress concentration in the connection portion can be reduced.

前記各実施形態では、正極４１，１１１の正極集電体の材質をアルミとし、負極４６，１１２の正極集電体の材質を銅としている。しかしながら、正極集電体及び負極集電体を他の材料によって構成してもよい。   In each of the above embodiments, the material of the positive electrode current collector of the positive electrodes 41 and 111 is aluminum, and the material of the positive electrode current collector of the negative electrodes 46 and 112 is copper. However, the positive electrode current collector and the negative electrode current collector may be made of other materials.

前記各実施形態では、破断箇所Ｘを有する正極リード５１，１３３を平面視で矩形状に形成している。しかしながら、正極リードが破断箇所Ｘで破断した場合に、その破断部分が負極と接触しないような形状であれば、正極リードの形状を他の形状にしてもよい。   In each of the above embodiments, the positive electrode leads 51 and 133 having the breakage point X are formed in a rectangular shape in plan view. However, when the positive electrode lead breaks at the breakage point X, the positive electrode lead may have another shape as long as the broken portion does not come into contact with the negative electrode.

前記実施形態１では、負極缶１０を外装缶とし、正極缶２０を封口缶としている。しかしながら、負極缶を封口缶とし、正極缶を外装缶としてもよい。   In the first embodiment, the negative electrode can 10 is an exterior can, and the positive electrode can 20 is a sealed can. However, the negative electrode can may be a sealed can and the positive electrode can may be an outer can.

前記実施形態１では、負極缶１０及び正極缶２０を、それぞれ有底円筒状に形成して、扁平形電池１をコイン状に形成したが、この限りではなく、扁平形電池を、多角柱状など、円柱状以外の形状に形成してもよい。また、前記実施形態２においても、ラミネート外装型電池１００を平面視で矩形状に形成しているが、この限りではなく、他の形状であってもよい。   In the first embodiment, the negative electrode can 10 and the positive electrode can 20 are each formed in a bottomed cylindrical shape, and the flat battery 1 is formed in a coin shape. However, the present invention is not limited thereto, and the flat battery is formed in a polygonal column shape or the like. The shape may be other than a cylindrical shape. Also in Embodiment 2, the laminate-cased battery 100 is formed in a rectangular shape in plan view, but is not limited to this and may have other shapes.

本発明による積層型電池は、衝撃が加わった際に正極リード及び負極リードの少なくとも一方が破断する積層型電池に利用可能である。   The multilayer battery according to the present invention can be used for a multilayer battery in which at least one of a positive electrode lead and a negative electrode lead is broken when an impact is applied.

１ 扁平形電池（積層型電池）
１０ 負極缶
２０ 正極缶（固定部材、ケース部材）
３０ ガスケット
４０ 電極体（積層体）
４１ 正極（第１の電極）
４２ 正極活物質層（正極材）
４３ 正極集電体
４３ａ Ｒ部
４４ セパレータ
４５ 正極本体部（本体部）
４６ 負極（第２の電極）
４７ 負極活物質層（負極材）
４８ 負極集電体
４９ 絶縁シート
５０ 負極本体部（本体部）
５１ 正極リード（接続部）
５２ 負極リード（接続部）
６１、６２ リード群
１００ ラミネート外装型電池（積層型電池）
１００ａ 膨出部
１００ｂ シール部
１１０ 積層体
１１１ 正極（第１の電極）
１１２ 負極（第２の電極）
１１３ セパレータ
１１５ 正極本体部（本体部）
１１６ 負極本体部（本体部）
１２０ ラミネートフィルム外装体（シート部材）
１３１ 正極外部端子（外部端子）
１３２ 負極外部端子（外部端子）
１３３ 正極リード（接続部）
１３４ 負極リード（接続部）
Ｘ 破断箇所（破断部） 1 Flat battery (stacked battery)
10 Negative electrode can 20 Positive electrode can (fixing member, case member)
30 Gasket 40 Electrode body (laminate)
41 Positive electrode (first electrode)
42 Positive electrode active material layer (positive electrode material)
43 Positive electrode current collector 43a R portion 44 Separator 45 Positive electrode main body (main body)
46 Negative electrode (second electrode)
47 Negative electrode active material layer (negative electrode material)
48 Negative electrode current collector 49 Insulating sheet 50 Negative electrode main body (main body)
51 Positive electrode lead (connection part)
52 Negative electrode lead (connection part)
61, 62 Lead group 100 Laminated exterior battery (laminated battery)
100a bulging portion 100b seal portion 110 laminate 111 positive electrode (first electrode)
112 Negative electrode (second electrode)
113 Separator 115 Positive electrode body (main body)
116 Negative electrode body (main body)
120 Laminate film exterior (sheet member)
131 Positive external terminal (external terminal)
132 Negative external terminal (external terminal)
133 Positive electrode lead (connection part)
134 Negative electrode lead (connection part)
X Breaking point (breaking part)

Claims (6)

平板状の第１の電極と、
前記第１の電極とは極性が異なる平板状の第２の電極とを備え、
前記第１及び第２の電極は、それぞれ、本体部と、平面視で該本体部から外方へ延びる接続部とを有し、該接続部が異なる方向に延びるように前記第１及び第２の電極の本体部同士が厚み方向に積層されていて、
前記第１の電極の接続部は、固定部材に固定されており、
前記第１の電極の接続部には、前記第１及び第２の電極を重ね合わせた状態で、平面視で該第２の電極の本体部外方の位置に、該第１及び第２の電極に衝撃が加わった際に破断する破断部が設けられ、
前記第２の電極の本体部は、その外形が平面視で前記第１の電極の本体部の外形よりも大きく、
前記固定部材は、前記第１及び第２の電極を積層してなる積層体を収納するためのケース部材である、積層型電池。 A flat first electrode;
A flat second electrode having a different polarity from the first electrode,
Each of the first and second electrodes has a main body portion and a connection portion extending outward from the main body portion in a plan view, and the first and second electrodes extend so that the connection portions extend in different directions. The electrode body parts are laminated in the thickness direction,
The connection portion of the first electrode is fixed to a fixing member,
Wherein the connecting portion of the first electrode, in the stacked state the first and second electrodes, the position of the body outer side of the second electrode in plan view, the first and second breaking portion is provided to break when impact is applied to the electrodes,
The main body portion of the second electrode has an outer shape larger than that of the main body portion of the first electrode in a plan view,
The stacked member is a stacked battery , wherein the fixing member is a case member for storing a stacked body formed by stacking the first and second electrodes . 平板状の第１の電極と、
前記第１の電極とは極性が異なる平板状の第２の電極と、
前記第１及び第２の電極を積層してなる積層体を覆うためのシート部材と、
前記シート部材の外方に一部が突出する外部端子とを備え、
前記第１及び第２の電極は、それぞれ、本体部と、平面視で該本体部から外方へ延びる接続部とを有し、前記第１及び第２の電極の本体部同士が厚み方向に積層されていて、
前記第１の電極の接続部には、前記第１及び第２の電極を重ね合わせた状態で、平面視で該第２の電極の本体部外方の位置に、該第１及び第２の電極に衝撃が加わった際に破断する破断部が設けられ、
前記第２の電極の本体部は、その外形が平面視で前記第１の電極の本体部の外形よりも大きく、
前記第１及び第２の電極の接続部のうち少なくとも一方は、前記外部端子に接続されている、積層型電池。 A flat first electrode;
A plate-like second electrode having a polarity different from that of the first electrode;
A sheet member for covering a laminate formed by laminating the first and second electrodes;
An external terminal partially protruding outward of the sheet member,
Each of the first and second electrodes has a main body portion and a connection portion extending outward from the main body portion in plan view, and the main body portions of the first and second electrodes are in the thickness direction. Are stacked,
In the state where the first and second electrodes are superposed on the connection portion of the first electrode, the first and second electrodes are disposed at positions outside the main body portion of the second electrode in plan view. A rupture part that breaks when an impact is applied to the electrode is provided,
The main body portion of the second electrode has an outer shape larger than that of the main body portion of the first electrode in a plan view ,
A stacked battery in which at least one of the connection portions of the first and second electrodes is connected to the external terminal. 請求項１または２に記載の積層型電池において、
前記破断部は、前記第１の電極の接続部において本体部寄りに設けられ、
前記破断部の幅は、前記第１の電極の接続部のうち当該破断部より本体部に近い部分の幅よりも小さく、且つ前記第１の電極の接続部のうち当該破断部より本体部から遠い部分の幅以下である、積層型電池。 The stacked battery according to claim 1 or 2 ,
The fracture portion is provided closer to the main body at the connection portion of the first electrode ,
The width of the rupture portion is smaller than the width of the connection portion of the first electrode closer to the main body portion than the rupture portion, and the connection portion of the first electrode from the main body portion to the rupture portion. A stacked battery that is less than or equal to the width of the far part . 請求項３に記載の積層型電池において、
前記第１の電極の接続部は、前記本体部から前記破断部に向かって徐々に幅が狭くなるようにＲ部が形成されている、積層型電池。 The stacked battery according to claim 3,
The connection part of the said 1st electrode is a laminated type battery by which R part is formed so that a width | variety may become narrow gradually toward the said fracture | rupture part from the said main-body part. 請求項１または２に記載の積層型電池において、
前記破断部は、前記第１の電極の接続部に設けられた切り欠き部である、積層型電池。 The stacked battery according to claim 1 or 2 ,
The rupture portion is a stacked battery, which is a notch provided in a connection portion of the first electrode. 請求項１から５のいずれか一つに記載の積層型電池において、
前記第１の電極は、リチウムイオンを吸蔵及び放出可能な正極材を有し、
前記第２の電極は、リチウムイオンを吸蔵及び放出可能な負極材を有する、積層型電池。 The stacked battery according to any one of claims 1 to 5 ,
The first electrode has a positive electrode material capable of inserting and extracting lithium ions,
The second electrode has a negative electrode material capable of inserting and extracting lithium ions.
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